This is a practice guideline. The components of this algorithm are evidence based wherever possible, but the sum of its parts has not been validated by any clinical studies.
DIAGNOSTIC ALGORITHM- The initial step prior to following the algorithm below is to perform a focused history and physical examination, and consider performing an ECG and or chest X-ray. Once a life- threatening etiology has been excluded, attempts should be make to identify the specific cause of symptoms and begin treatment

Step 1: Evaluate need for emergent care: Consider potentially life-threatening causes of chest pain. Patients it whom an ACS ( acute coronary syndrome: acute myocardial infraction or unstable angina) is suspected should receive emergent care ( chewing an aspirin).
Emergent care should also be provided to patients who appear to be seriously ill and to patients in whom there is a suspicion a critical noncoronary diagnosis such as pulmonary ambolus, pneumothorax, aortic dissection, esophageal rupture or acute abdomen. For the patients who do not require emergent care , proceed to step 2.

Step 2: Emergent care not needed. In patients in whom a diagnosis of stable CHD ( coronary heart disease or coronary artery disease) appears likely based on symptoms that are suggestive of angina and/or a history of cardiac rick factor, proceed to step 3, otherwise , proceed to step 5.

Step 3: Symptoms consistent with stable angina: Evaluate the patient for CHD, and consider staring outpatient managerment (therapy may be include aspirin, beta-blocker, nitroglycerin, and education about need for emergency care ) or admitting the patient to the hospital , especially if symptoms are progressive. It there is a concerm for angina secondary to valvular heart disease (eg, critical aortic stenosis), perform an echocardiogram prior to stress testing. Consider other cause of anginal chest pain , such as cardiac syndrome X and pulmonary hypertension. If the results of the evaluation do not demonstrate CHD, proceed to step 4, overwise, proceed to step 8.

Step 4: Evaluation for CHD was negative: Evaluate the patient for gastrointestinal disease. This evaluation may initially involve a trial of acid suppression. If there is no diagnosis and symptoms persist, proceed to step 6, overwise , proceed to step 8

Step 5: Symptoms not sugestives of angina

Step 5a:For patients who are felt not to have an ischemic etiology for chest pain but who have significant rick factor for CHD, stress testing , while proceeding to step 5b

Step 5b: If symptoms suggest a musculosketetal etiology , a trial of an NSAID is appropriate, overwise, proceed to step 5c. If the pain persists, consider rib films, a bone scan, and plain or CT chest radiography. If there is no diagnosis and symptoms persist , proceed to step 6. otherwise, proceed to step 8

Step 5d: If symptom suggest a psychogenic etiology, evaluate the patient for a psychosocial soure of chest pain, overwise, proceed to step 5e. Diagnosis strategies may be include a therapeutic trial of an antidepressant medication of a psychiatric referral. If there is not diagnosis and symptoms persist , proceed to step 6. overwise proceed to step 8.

Step 5e: Consider chest anatomy as a guide to other less common causes of non-life-threatening chest pain including; chest wall pain ( eg, zorter, breast disease) ; other cardiac pain such as pericarditis; pathology of lung parenchyma, vasculature , or pleura, and pain refferred to chest from the gallbladdder , diaphragm, or from a disc herniation.

Step 6: Persistent chest pain: If the pain persists and evaluation for CHD ( as in step 5a), musculasketetal pain ( as in step 5b), gastrointestinal pain ( as in step 5c) , psychogenic pain ( in step 5d) , and other causes ( as in step 5e) have not all been performed , those evaluations should now be undertaken.
If there is no diagnosis and symptoms persist, proceed to step 7, otherwise , proceed to step 8

Step 7: Diagnosis evaluations negative: patient likely has chronic idiopathic chest pain. Since this is know to cause significant disability, consider referral to pain management center or medical symptom reduction program. No futher evaluation is required unless the patient has a change in symptoms or the symptoms are disabling .

Step 8: Cause of chest pain diagnosed: Proceed with therapy or additional evaluation as appropriate for the diagnosed condition.